Chemistry Reference
In-Depth Information
Safety Note
Goggles must be worn at all times during this
experiment. Manganese dioxide and potassium permanganate are
strong oxidizing agents and may cause permanent staining of skin and
clothing. please review and follow the safety guidelines at the beginning
of this volume.
Procedure
1. Label two beakers “with catalyst” and “without catalyst.”
2. Measure 50 milliliters (ml) of 6 percent hydrogen peroxide and pour
into a beaker. Repeat for the second beaker.
3. Place a plastic weigh boat on a balance and tare. Mass out 0.5
grams (g) of manganese dioxide into the weigh boat.
4. Add the manganese dioxide to the “with catalyst” beaker. Allow the
substances to react until the bubbling slows.
5. Set up a burette on a ring stand with a burette clamp. Using a
funnel, fill the burette with potassium permanganate. Use caution,
as potassium permanganate will stain skin and clothing.
6. Remove 5 ml of the peroxide from the “without catalyst” beaker and
add to a separate beaker.
7. Record the initial volume of the burette.
8. Titrate the hydrogen peroxide in the “without catalyst” beaker. To
do so, add potassium permanganate to the beaker containing 5 ml
of hydrogen peroxide, one drop at a time, until the solution in the
beaker turns a very faint pink to brown color that lingers. Record
the final volume of the burette on your data table. Keep these points
in mind:
If the solution turns dark pink, brown, or purple, you must
✔
start over with another 5 ml sample from the same beaker.
It is not necessary to refill the burette between trials, but you
✔
must record the new initial volume before beginning.
If the burette runs out of potassium permanganate, it will
✔
need to be refilled. Make sure that you keep track of the
volume used before you refill the burette.
9. Subtract the initial volume from the final volume to determine the
total volume of potassium permanganate used. Record the volume
in the appropriate column of the data table.
